Vapor electric apparatus.



PATENTBD EEf-B. 7, 1905.

J. T. H. DEMPSTBR. VAPOR ELECTRIC APPARATUS.

APPLICATION IILED JUNE 27. 1904.

Fig.1.

INVEMTOR UNITED STATES JOHN T. H. DEMPSTER, OF SOHENEOTA DY, NEWV YORK, ASSIGNOR TO GEN- Patented February 7, 1905.

PATENT OFFICE.

ERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

VAPOR ELECTRIC APPARATUS.

SPECIFICATION forming part of Letters Patent No. 781,938, dated February 7, 1905,

Application filed June 27, 1904. Serial No. 214,240.

To 1/. whom it 7111/01/ concern/.-

Beit known thatl, JOHN T. H. Dnnrs'rnn, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Vapor Electric Apparatus, of which the following is a specification.

My invention relates to vapor electric devices-such, for example, as mercury-vapor 1 lamps, rectifier-s, or the like-and comprises improvements more especially directed to means for starting such devices into operation.

The novel features of my invention are pointed out with particularity in the appended 5 claims. The invention itself, however, will be better understood by reference to the following description, taken in connection With the accompanying drawings, in Which- Figure 1 represents my invention as applied 20 to a mercury-vapor lamp, while Fig. 2 is a cross-sectional view of a portion of Fig. 1.

The apparatus to which my invention is applicable may be of divers shapes and kinds. For the sake of illustration, however, 1 have in Fig. 1 represented my invention as applied to a vertical-tube mercury-vapor lamp. The exhausted envelop or container of the lamp consists of a light-emitting tube 1, of glass or other suitable material, surmounted by an enlargement or bulb 2, constituting a condensing-chamber for the surplus mercury vapor generated during operation. The tube may be of indefinite length.

The upper electrode of the lamp may consist, as shown, of a hollow cylindrical body 3, of carbon or graphite, suspended from the leading-in conductor 4:. This wire is surrounded and protected by a glass tube 5, extending from the top of the bulb 2 down to 4 and flaring slightly over the top of the electrode 3. A filament 6, of carbon or other suitable material, is suspended from the electrode 3 and extends down through suitable anchoring devices 7 and 8, through which it passes loosely to within proximity to a body of mercury 9, contained within the bifurcated end of the tube 1. These limbs or bifurca- LII I tions 10 and 11 are filled with mercury to a l depth such that the mercury just bridges over the portion 12 of the container separating the limbs or bifurcations. The crosssection through this point, Fig. 2, shows the mercury over the portion 12 a little more clearly. Each of the limbs 10 and 11 is provided with a leading-in conductor, as at 13 and 14.

A powerful electromagnet 15 of the horseshoe type is arranged with its poles on either side, respectively, of the thread or body of mercury connecting the two main bodies in the limbs 10 and 11, so that a powerful magnetic flux cuts across this thread or section of the mercury. The magnetizing-coil of the magnet is indicated at 16.

In connecting the lamp in circuit one of the direct-current mains extends to the leading-in conductor 13. This main is indicated at 17. The other main, 18, is connected, through the coil 19 of a cut-out, to a leading-in conductor -L of the upper electrode 3. This same main is also connected, through the coil 16 and through a resistance 20, if desired, to the remaining leading-in conductor H.

Upon the application of current to the lamp the current first flows from the main 18 through the coil of the magnet 16 to the leading-in conductor 11, thence through the mercury of the lamp to the other leading-in conductor, 13, and thence to the other main, 17. The magnetic field produced by the magnet 15, acting upon the current passing through the section of mercury 12, produces a repelling action thereon which has the effect of causing a separation of this strip or thread of mercury. As soon as this takes place the current which heretofore flowed directly through the mercury now flows in the form of an are between the adjacent mercury-surfaces. The mercury being thus ionized, or, in other words, caused to produce conducting mercury vapor, then becomes the startingpoint of an electric are or discharge which passes immediately up the tube 1 to the positive electrode or anode 3. In this operation the passage of the arc is greatly assisted by the presence of the filament 6. When this state of affairs is reached, current fiows di rectly from the main 18, which is the positive main, through the lamp to the mercury 1 and then to the other or negative main 17. The cut-out 19 is thus energized and by acting upon its core 21 lifts the short-circuiting device 22 and opens the circuit of the electromagnet 15. The starting-arc which operated to put the lamp in operation is thus extinguished, though, if desired, it may be allowed to continue coexistently with the main current of the lamp between the main positive electrode 3 and the negative mercury electrode.

It is evident that various modifications and adaptations of my invention may be made Without departing from the spirit thereof. For this reason I do not wish to be limited to the exact details shown and described.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In a vapor electric apparatus, the combination of an envelop containing fluid electrodes normally connected by a body of fluid of relatively small cross-section, and means i for applying a magnetic field to-this body of fluid.

2. The combination of fluid electrodes normally connected, means for causing an electric current to pass between said electrodes,

and means for causing an electrodynamic ac-' tion between a magnetic field and the current flowing between said electrodes.

3. The combination of an exhausted envelop or container, a main positive electrode. a combined negative electrode and positive electrode consisting normally of coalescing bodies of mercury, means for passing current through said mercury, and means acting upon said current for breaking the continuity of the mercury between said electrodes.

4:. The combination of an envelop or container, a body of conducting fluid therein, means for passing current through said fluid, and means acting upon said current for producing an interruption in its path through the fluid.

In witness whereof I have hereunto set my hand this 25th day of June, 1904.

JOHN T. H. 'DEMPSTER.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD. 

